Depression is a common psychiatric disorder that its prevalence has been reported to be 16% among adults. In recent years,
transcranial near-infrared laser therapy (NILT) has gained considerable attention as a novel non-pharmaceutical method
for depression. The present study was designed to compare the efficacy of two different treatment strategies in a rat model
of depression. Forty male Wistar rats (180-200 g) divided into 4 groups: control, depressive, depressive-NILT, and
depressive-Citalopram. All animals excepted control group was exposed to chronic mild stress (CMS) for 4 weeks. Rats
in laser group received 10-Hz pulsed NILT (810 nm, energy density 1.2 J/cm2 per session) transcranially for a total of 12
sessions over a three-week period. Citalopram (10 mg/kg, Intraperitoneal) was administered for 21 consecutive days.
Depressive-like behavior was tested in the forced swimming test (FST) model. Serum cortisol levels were also determined.
The results of FST showed an increase in swimming and decrease in immobility period, for both NILT and Citalopram
groups compared to the stress group. There was also no significant difference between the experimental groups in climbing
behavior. The induction of CMS significantly increased serum cortisol levels and treatments with NILT and Citalopram
decreased it. Our findings showed that NILT will be more beneficial to improve the depressive-like behaviors in the rat.
Our data also showed that transcranial NILT was as effective as Citalopram in the treatment of depression. Therefore,
these pieces of evidence may help improve NILT as an alternative non-pharmaceutical method for depression therapy.